Microsoft Defender Denial of Service Vulnerability
Priority LOW 27Published · Updated
Key facts
- Attack vector
- Local
- Privileges required
- None
- User interaction
- Required
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA.
Summary
Microsoft Defender Denial of Service Vulnerability
Why it matters now
EPSS 0.01225 68th percentileScored 2026-11-07
Fix Fixed Microsoft Malware Protection Engine (Microsoft): Version 1.1.18200.3
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Microsoft | Microsoft Malware Protection Engine | 1.1.0.0 to before Version 1.1.18200.3 | Version 1.1.18200.3 | Patch available | CNA |
- Microsoft Malware Protection Engine VendorMicrosoft Affected 1.1.0.0 to before Version 1.1.18200.3 Fixed in Version 1.1.18200.3 Patch available CNA
Remediation
- Fix · CNA Microsoft Malware Protection Engine (Microsoft) Fixed in Version 1.1.18200.3
Timeline
- 2026-10-02 Threatist record created from CVE-2021-31978
- 2026-10-03 Alias added: GHSA-9mqr-qv46-7v82
More Microsoft Malware Protection Engine vulnerabilities
- TI-2026-29727 Microsoft Defender Elevation of Privilege Vulnerability KEVCVSS 3.1HIGH 7.8
- TI-2017-06074 Out-of-bounds write in Microsoft Malware Protection Engine KEVCVSS 3.1HIGH 7.8
- TI-2017-00265 Memory corruption in Microsoft Malware Protection Engine CVSS 3.0HIGH 7.8
- TI-2026-48742 Microsoft Defender Elevation of Privilege Vulnerability CVSS 3.1HIGH 7.8
- TI-2026-37344 Microsoft Defender Elevation of Privilege Vulnerability CVSS 3.1HIGH 7.8
- TI-2017-06072 Memory corruption in Microsoft Malware Protection Engine CVSS 3.0HIGH 7.8
Sources
- CVE-2021-31978 · CVE Program
- CVE-2021-31978 · NVD
- FIRST EPSS
- GHSA-9mqr-qv46-7v82 · GitHub Advisory Database · CC BY 4.0
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